Maple Leaf has recalled some wieners over fears of listeria contamination. (Canadian Press)

Nine wiener products have been recalled by Maple Leaf Foods Inc. because of concerns the meat may contain traces of listeria monocytogenes.

There have been no reported illnesses connected to the wiener products and the recall is only a precaution, Maple Leaf said Tuesday in a release.

"Maple Leaf is doing more aggressive and frequent Listeria testing at our plants than regulations require, and that means we're finding it more," the company said.

The products have been distributed nationally and should not be consumed even though they do not appear to be spoiled, according to the release.

"An investigation took place at the plant," CFIA spokesman Fred Jamieson told CBC News. "And based on the evidence that we had, Health Canada gave us a highest risk assessment for the products."

A highest risk assessment implies there is a chance of more severe symptoms with high-risk groups such as the pregnant women, the elderly or the infirm if they consume the bacteria.

The wieners were produced at a facility in Hamilton, Ont., under brand names that include Hygrade, Shopsy's and Maple Leaf. The best-before dates on the recalled products range from Sept. 8 to Sept. 17.

The nine products are:

• Hygrade Wieners.
• Shopsy's Deli-Fresh All Beef Frankfurters.
• Shopsy's Deli-Fresh All Beef Wieners.
• Shopsy's Deli-Fresh Regular Frankfurters.
• Maple Leaf Original Wieners.
• Maple Leaf Top Dogs All Beef Wieners.
• Maple Leaf Top Dogs Original Wieners.
• Maple Leaf Top Dogs Original Wieners BBQ Size.
• Maple Leaf Top Dogs, 33% Less Fat.

The numbers for the Hamilton plant — EST. 611 and L1 — are on an inkjet stamp located on the edge of the packaging.

All the products still on the market have been voluntarily recalled.

Last summer, 22 people died and hundreds more fell ill after eating contaminated deli meats linked to a Maple Leaf Foods plant in Toronto.

"At this point, there is no connection," between the two plants, Jamieson told CBC News. "They are two separate plants, one being in Hamilton and one being in Toronto."

Dr. Randall Huffman, the chief food safety officer at Maple Leaf, said in a statement the company is now "ultra-cautious about listeria."

Huffman said the Hamilton plant has a very strong food safety testing and sanitation program and the listeria bacteria found in random product samples is at very low levels.

People who eat foods contaminated with listeria may carry the bacteria and still not develop listeriosis. Symptoms of listeriosis can include high fever, severe headache, neck stiffness and nausea.

With files from The Canadian Press